Drill stem testing packers, pipe, and couplers



A. BARRY 3,032,116

DRILL S I'EM TESTING PACKERS, PIPE, AND COUPLERS May 1, 1962 2 Sheets-Sheet 1 Filed Dec. 11, 1958 INVENTOR.

ADELBERT BARRY ATTORNEY.

n IIII!I!lllllllrlflllfflllflllld DRILL STEM TESTING PACKERS, PIPE, AND COUPLERS Filed Dec. 11. 1958 A. BARRY 2 Sheets-Sheet 2 May 1, 1962 8 7 M 2 8 G W m w I w 3 w my w Y M m 0 w A O T w T s a 8 MW F O 0 w w 5 5 A TTORNEY.

nited Sttes atent 3,032,116 DRILL STEM TESTING PACKERS, PIPE, AND COUPLERS Adelbert Barry, Houston, Tex., assignor, by mesne assignments, to Jersey Production Research Company,

Tulsa, Okla., a corporation of Delaware Filed Dec. 11, 1958, Ser. No. 779,636 Claims. (Cl. 166--187) This invention concerns apparatus for conducting subsurface formation tests and, in particular, packers, perforated pipe, and couplers for up hole straddle-pack drill stem testing.

In drilling wells for the production of fluids, especially the production of petroleum fluids, samples of formation fluids are obtained during drilling operations, generally termed drill stern testing, in order to determine the type or types of fluid contained in the formation traversed by the borehole being drilled.

At times it is necessary to obtain a fluid sample from a formation located some distance from the bottom of the borehole. In this situation, it has been the practice to set two packers having a section of perforated pipe therebetween above and below, that is, to straddle, the formation to be tested. The test fluids flow through the section of perforated pipe and to the drill stern located above the packers. For a successful test, it is necessary to equalize the mud pressure in the well annulus by connecting the annulus above the top packer to the annulus below the bottom packer.

Also, it has been the practice when making drill stem tests employing compression type packers to run a pipe passage between the upper and lower annulus. This pipe is located centrally within the perforated pipe section arranged between the packers. This type of arrangement is disadvantageous because it is a time consuming and risky procedure because pipe couplings are employed and leaks which develop will communicate the formation fluid to the mud annulus with resulting failure of the test. With inflation type packers it is necessary to provide an inflating line to the bottom packer through the perforated section in addition to the equalizing line to communicate the well annulus above the upper packer and below the lower packer. This procedure is even more disadvantageous for leaks which develop through the couplings will result in failure of the test and further, leaks in the inflating line will result in failure of the packers to inflate.

The present invention overcomes these disadvantages by providing equalizing passages in the walls of the perforated pipe sections and in the walls of the packer mandrels. These equalizing passages extend longitudinally. Couplers are provided at the pipe section joints and at the joints between the pipe sections and the packer mandrels which couplers are provided with equalizing passages in the walls thereof extending longitudinally of the axes of the couplers. Seals are provided on each coupler at the connections between the equalizing passages to form an isolated conduit extending from above the upper packer to below the lower packer. When employing inflatable type packers similar sealed longitudinally extending inflate passages are formed in the walls of the mandrels, couplers, and perforated pipe sections to form an isolated conduit for conducting packer inflate fluid to the packers. Recesses may be provided on the couplers adjacent the ends of the equalizing and inflate passages in order to insure fluid communication between the passages when the joints are made up.

Thus, one object of the present invention is to provide a new and improved arrangement of apparatus for straddle-pack drill stern testing.

This and other objects of the invention will be apparent from a more detailed description of the invention taken in conjunction with the drawings wherein:

FIG. 1 is an elevational view of the apparatus of the invention arranged in a borehole;

FIGS. 2 and 3 are elevational views, partly in section, showing the apparatus of the invention between arrowed lines 2-2 and 3-3, respectively, of FIG. 1 in greater detail;

FIG. 4 is an elevational, sectional view of the upper coupler connection;

FIG. 5 is a view taken on lines 5-5 of FIG. 4;

FIG. 6 is a view taken on lines -6 of FIG. 4;

FIG. 7 is an enlarged view of the valving arrangement shown in FIG. 2; and

FIG. 8 is an elevational view of a modified arrangement of the apparatus showing a plurality of interconnected couplers.

In FIG. 1 is shown a borehole 10 penetrating a subsurface formation 11. Apparatus is arranged in borehole 10 for conducting fluids from formation 11 to the appropriate testing equipment connected to a drill stem or pipe and includes the lower end of a drill pipe or drill stem 12 to which is connected a packer inflating fluid pump section 13, an upper packer section 14, a perforated pipe section 15, a lower packer section 16 and a drill bit (or anchor shoe) 17.

Pump section 13 includes a piston rod 18, and a cylinder 19. Upper packer section 14 includes an inflatable packer 20 adapted to expand to seal off the annulus A between the apparatus and the borehole wall above formation 11 and an equalizing port 21 positioned above packer 2!). Pipe section 15 is provided with a plurality of perforations 22 adapted to conduct fluids from formation 11 to the interior of pipe 12. Lower packer section 16 includes an inflatable packer 23 adapted to seal ofl the annulus A between the apparatus and the borehole wall below formation 11 and an equalizing port 24 below packer 23. Drill bit 17 may be plugged prior to making the drill stem tests in order to prevent fluids in annulus A from entering pipe 12 through the bit or instead a plug may be employed in place of drill bit 17.

Details of pump section 13, packer sections 14 and 16 and pipe section 15 are shown in FIGS. 2 and 3. A cylinder-sub or closure member 25 formed to provide a packer inflate passageway 26 and a fill-passageway 27 is conected to the lower end of pump cylinder 19. A valve assembly 28 (see FIG. 7) is arranged in passageway 26 and passageway 27 is provided with a removable plug 29. A guide head 31 is connected to the upper end of cylinder 19. A piston 32 to which is connected a hollow plunger or piston rod 18 extends through guide head 31 and connects to pipe 12. The interior surface of plunger 18 is circular and the exterior surface thereof is square. The interior of guide head 31 also is formed square thereby providing a keyway in guide head 31 which prevents rotation of plunger 18 relative to cylinder 19. This structure is desirable for operation of certain standard test tools which require rotary motion for operation.

A pipe or stringer 33 which fluidly communicates with a central passageway 30 formed in closure member 25 is secured to closure member 25 and extends through piston 32 into the interior of plunger 18. Packer inflating fluid 34 is contained in cylinder 19. Sealing means 35 are arranged on piston 32 adapted to seal off the annulus between piston 32 and the interior wall of cylinder 19 and sealing means 36 is arranged on piston 32 adapted to seal oil the annulus between piston 32 and the exterior wall of pipe 33. Sealing means 37 is arranged in closure member 25 adjacent passageway 30 adapted to seal off the annulus between pipe 33 and closure member 25.

An upper packer pipe or mandrel 40 is screw-threadedly connected to closure member 25. Mandrel 46 has arranged thereon inflatable packer 26. An equalizing passage 41 is formed to extend longitudinally through the wall of mandrel 4t) and fluidly communicates equalizing port 21 and the interior or bore 42 of mandrel 40. Mandrel 46 also is provided with a longitudinally extending packer inflate fluid passageway 43 and a port 44 intermediate the length thereof, the latter port fluidly communicating passageway 43 and the interior of packer 20. Passageway 43 fluidly communicates the lower end of passageway 26 with port 44 and with the bore 42 of mandrel 40. Closure member 25 is provided with upper and lower seals 45 and 46 to seal off the space between the upper end of mandrel 4-5 and closure member 25 above and below the interconnection of passageways 26 and 43, respectively. An annular recess 47 is formed in closure member 25 adjacent the lower end of passageway 26 to insure fluid communication between passageways 26 and 43 when mandrel 40 is connected to closure member 25.

Pipe section 15 is screw-threadedly connected to the lowe rend of mandrel 4d and includes at least one section of pipe Sit provided with perforations 22 which fluidly communicate the bore and exterior thereof. Pipe 50 is also provided with a longitudinally extending equalizing passageway 51 formed in the wall thereof. Passageway 51 fluidly communicates with the bore of pipe 59 at its upper and lower ends. Pipe 56 is also provided with a longitudinally extending packer fluid inflate passageway 52 formed in the walls thereof. Passageway 52 also fluidly communicates with the bore of pipe 54 at its upper and lower ends. Perforations 22 of pipe t) are spaced to avoid passageways 51 and 52. A lower packer mandrel 55 of packer section 16 is screw-threadedly connected to the lower end of pipe 5i Mandrel 55 is provided with a longitudinally extending equalizing passageway 56. The lower end of passageway 56 fluidly communicates with equalizing port 24 and the upper end fluidly communicates with the bore 57 of mandrel 55. M-andrel 55 also is provided with a longitiudinally extending packer fluid inflate passageway 58. The lower end of passageway 58 fluidly communicates with the interior of packer 23 and the upper end fluidly communicates with the bore of mandrel 55.

The lower end of mandrel 40, the upper end of pipe 50, the lower end of pipe 50, and the upper end of mandral 55 are provided with recessed portions designated 60, 61, 62 and 63, respectively. Couplers 65, shown in greater detail in FIG. 4, are arranged in these recessed portions.

As seen in FIG. 4, coupler 65 is provided with a bore 66 extending therethrough and fluidly communicating with the bore 50 of pipe 5%} and the bore 42 of mandrel 40. Also, a longitudinally extending equalizing passageway 67 terminating in spaced annular recesses 68 and 69 adjacent the outer surface of coupler 65 is provided in the wall thereof. Additionally, a longitudinally extending packer fluid inflate passageway 76 terminating in spaced recesses 71 and 72 adjacent the outer surface thereof is provided in the wall of coupler 65. Passageway 67 fluidly communicates at its upper end with passageway 41 and the interconnection of these passageways is sealed off by means of spaced seals 73 and 7 a, respectively. The lower end of passageway 67 fluidly communicates with passageway 51 and the interconnection between these passageways is sealed olf by means of spaced seals 76 and 77. The upper end of passageway 70 fluidly communicates with passageway 43 and the interconnection between these passageways is sealed off by means of spaced seals 74 and 75. The lower end of passageway 70 fluidly communicates with passageway 52 and the interconnection of these passageways is sealed off by means of spaced seals 77 and 78, respectively. Annular recesses 68, 69, 71, and '72 are provided in order d to insure fluid communication between the various passageways when the joint is made up.

The lower coupler is identical in construction to the coupler just described; however, in this instance, passageway 52 fluidly communicates with passageway which, in turn, fluidly communicates with passageway 58 and passageway 51 fluidly communicates with passageway 67 which, in turn, fluidly communicates at the lower end with passageway 56.

FIGS. 5 and 6 show the arrangement of the passageways adjacent the upper and lower ends, respectively, of the coupler more clearly. The valve assembly 28, shown in detail in FIG. 7, is arranged in passageway 26. The upper portion of passageway 26 fluidly communicates with two oppositely disposed check valves 82 and 83 which, in turn, fluidly communicate with the lower portion of fluid passageway 26 via conduits or branch passageways 84 and 85, respectively. A plug 86 is arranged in closure member 25 for facilitating positioning and re moval of valve elements 82 and 83. Sealing means 87, which may be suitably O-ring seals, are provided for sealing off the various flow passages. Check valves 82 and 83 include spring members 88 and 89, respectively, and ball members 90 and 91, respectively. Spring member 89 is of sufficient strength to prevent movement of fluid from cylinder 19 through the upper portion of fluid passageway 26 to fluid passageway and the lower portion of fluid passageway 26 when the piston is in the upper position. I

In operation, when it is desired to test the fluids of formation 11 setting down of weight upon drill string 12 causes plunger 18 to move downwardly within cylinder 19. Packer inflating fluid 34 is thereby forced by piston 32 downwardly through fluid passageway 26 through valve 28, which valve permits downward flow through passageway 26 when piston 32 moves downwardly and permits flow of fluid upwardly through passageway 26 when piston 32 is moved upwardly, through passageway 43 into the interior of packer 2th through port 44 and through passageway 76, through passageway 52, through passageway 70 of lower coupler 65, and through passageway 58 into the interior of packer 23. When packers 20 and 23 have expanded into engagement with the borehole wall, formation fluids move through perforations 22 into the bore of pipe 50 through the bore 66 of coupler 65, through the bore 42 of mandrel 40, through passageway 30, through pipe 33 and plunger 18, and into the interior of pipe string 12. Mud pressure in annulus A above packer 20 and below packer 23 is equalized through port 21, passageway 41, passageway 67 in upper coupler 65, passageway 51, passageway 67 in lower coupler 65, passageway 56, and port 24.

Lifting of weight from drill string 12 permits packers 2t) and 23 to deflate as plunger 18 is withdrawn upwardly to return the inflate fluid back into cylinder 19. Thus, when weight is released from drill string 12, piston 32 moves upwardly and fluid within packer 23 is conducted through passageway 58, passageway 70 in lower coupler 65, passageway 52, passageway 70 in upper coupler 65, passageway 43, and passageway 26 into cylinder 19 and fluid within packer 20 is conducted to cylinder 19 through port 44, passageway 43, and passageway 26.

The various seals mentioned in the description may be suitably O-ring seals.

Although, two couplers 65 have been shown and described, one interconnecting the upper end of pipe 50 and an upper packer mandrel and the other interconnecting the lower end of pipe. 50 and a lower packer mandrel, it is to be understood that additional couplers may be provided where necessary. For example, as shown in FIG. 8, several sections of perforated pipe 50 may be desired in which case a coupler 65 may be employed at each joint. Thus, long straddle distances may be easily accommodated by the simple procedure of as sembling a short perforated pipe section above, or on top of the bottom packer, then inserting a coupler, then another perforated section, etc.

Having fully described the nature, objects, apparatus, and operation of my invention, 1 claim:

1. Apparatus for testing a subsurface formation penetrated by a well bore having a pipe string arranged therein comprising a packer inflate pump adapted to contain a predetermined amount of packer inflate fluid and connected to said pipe string and having a packer inflate passage; valve means arranged in said inflate passage adapted to prevent fluid flow downwardly through said inflate passage except when said fluid is forced therethrough by said pump; an upper packer mandrel connected to said pump; an inflatable packer arranged on said upper mandrel adapted to seal off the annulus between said upper mandrel and said borehole wall when inflated; at least one section of perforated pipe connected to said upper mandrel; a lower packer mandrel connected to said perforated pipe; an inflatable packer arranged on said lower mandrel adapted to seal off the annulus between said lower mandrel and said borehole wall when inflated; said upper mandrel, said perforated pipe, and said lower mandrel, each having a bore therethrough, a packer inflate passage, and a pressure equalizing passage; said upper mandrel packer inflate passage extending from the upper exterior to the lower interior of said mandrel and fluidly communicating with the interior of the packer intermediate the length thereof; said upper mandrel equalizing passage extending from the upper exterior above the upper packer to the lower interior of said mandrel, each of said perforated pipe inflate and equalizing passages extending from the upper interior to the lower interior of said pipe; said lower mandrel packer inflate passage extending from the upper interior to the exterior intermediate the length thereof surrounded by said lower packer; said lower mandrel equalizing passage extending from the upper interior to the lower exterior below said lower packer; upper and lower couplers arranged in the bores between said upper mandrel and said perforated pipe and said lower mandrel and said perforated pipe; each coupler having a bore therethrough, an inflate passage and an equalizing passage; the inflate and equalizing passages extending from the upper exterior to the lower exterior of said coupler; each passage terminating in annular recesses; sealing means arranged above and below each recess adapted to seal off the space between the exterior of the coupler and the interior of the pipe and mandrels; the inflate passages in said pump, upper mandrel, upper coupler, pipe, lower coupler, and lower mandrel being in fluid communication and the equalizing passages in said upper mandrel, upper coupler, perforated pipe, lower coupler, and lower mandrel being in fluid communication whereby pressure above said upper packer and below said lower packer is equalized through said equalizing passages when said packers are inflated by pumping fluid through said inflate passages.

2. Apparatus for testing a subsurface formation penetrated by a well bore having a pipe string arranged therein comprising a packer inflate pump adapted to contain a predetermined amount of packer inflate fluid and having a packer inflate passage and connected to said pipe string; valve means arranged in said inflate passage adapted to prevent fluid flow downwardly through said inflate passage except when said fluid is forced therethrough by said pump; an upper packer mandrel conneoted to said pump; an inflatable packer arranged on said upper mandrel adapted to seal off the annulus between said upper mandrel and said borehole wall when inflated; a perforated pipe connected to said upper mandrel; a lower packer mandrel connected to said perforated pipe; an inflatable packer arranged on said lower mandrel and adapted to seal off the annulus between said lower mandrel and said borehole wall when inflated; said upper mandrel, said perforated pipe, and said lower mandrel each having a bore therethrough, a packer inflate passage, and a pressure equalizing passage; upper and lower couplers arranged in the bores between said upper mandrel and said perforated pipe and said lower mandrel and said perforated pipe; each coupler having a bore therethrough, an inflate passage, and an equalizing passage; said inflate passages being in fluid communication and providing an isolated conduit extending from said pump inflate passage to the interiors of said packers; and said equalizing passages being in fluid communication and providing an isolated conduit extending from the exterior of the upper mandrel above said upper packer to the exterior of the lower mandrel below the lower packer.

3. Apparatus as recited in claim 2 including each coupler passage terminating in a recess and said coupler being provided with seals adapted to seal off the interconnections between the recesses and the various passageways.

4. Apparatus for use in interconnecting two sections of pipe, each section having a bore therethrough, a longitudinally extending packer inflate passage and a longitudinally extending equalizing passage comprising a conpler adapted to flt in the bore of said pipe between the sections thereof in order to fluidly connect the sections and having a bore therethrough fluidly connecting with said pipe bores, a longitudinally extending inflate passage and a longitudinally extending equalizing passage; each passage terminating at the ends thereof in an annular recess which fluidly communicates with the respective inflate and equalizing passages in said pipe sections; and sealing means arranged above and below each recess adapted to seal off the interconnections between these passages.

5. Apparatus for use in interconnecting two sections of pipe, each section having a bore therethrough and first and second longitudinally extending passages therein comprising a coupler adapted to fit in the bore of said pipe between sections thereof in order to fluidly connect the sections and having a bore therethrough fluidly connecting with said pipe bores and two longitudinally extending passages; one of said coupler passages terminating at each end thereof in annular recesses, one of which fluidly connects with said first passage in one pipe section and the other of which fluidly connects with said first passage in said other pipe section and said other coupler passage terminating at each end thereof in an annular recess, one of which fluidly connects with said second passage in said one pipe section and the other of which fluidly connects with said second passage in said other pipe section.

References Cited in the file of this patent UNITED STATES PATENTS 2,621,743 Johnston Dec. 16, 1952 2,633,200 Humason Mar. 31, 1953 2,675,080 Williams Apr. 13, 1954 2,741,313 Bagnell .-Apr. 10, 1956 2,793,524 Badger May 28, 1957 2,806,539 Green et al Sept. 17, 1957 2,813,587 Mounce Nov. 19, 1957 

